Conventionally, there is known a so-called built-in type air conditioner in which an air conditioner main body is installed in the ceiling, for example, of a room to be air-conditioned, and the air having been subjected to heat exchange with a heat exchanger accommodated in the air conditioner main body is supplied to the room to be air-conditioned (called “air-conditioned room” hereinlater) via a blow-out duct.
The air conditioner of this type includes, in addition to the heat exchanger and a blower, an electric (or electrical) component box in which electric (or electrical) components or parts such as a printed board (a control board or a circuit board) with electronic components or parts mounted thereon are accommodated. The electric components in the electric component box generate heat when the air conditioner operates, and it is hence necessary to cool these electric components.
To cool the electric components, it might be possible to adopt a configuration in which a plurality of vent holes are provided in the electric component box so as to cool the inside of the electric component box. However, when a fire occurs in the electric component box, the fire may spread to the air conditioner main body and the building materials in the ceiling through the vent holes. On the other hand, when the electric component box is configured as a sealed structure in order to prevent the spread of the fire from the electric component box, the heated electric components is cooled insufficiently, which may cause failures in or malfunctioning of the electric components.
Further, there is a case where, in order to promote cooling of the inside of the electric component box, a cooling structure is adopted in which a plurality of vent holes are provided in the electric component box, or in which a hole is provided in the electric component box so that a cooling member such as a heat sink is arranged to project outward from the inside of the electric component box.
In such a case, in a known configuration, a sheet material is provided to close a gap formed between the heat sink and the hole provided in the electric component box.
In the structure described above, since the temperatures of the heat sink and the electric component box become high, the sheet material provided in the manner mentioned above is not stuck or bolt-fixed to the heat sink and the electric component box, and hence, easily falls off during assembly or maintenance. Thus, this may result in deterioration of workability and insufficient cooling of the heat-generating electric components and eventually may result in failure or malfunction of the electric components.